The Tandata QL modems consisted of a three-stack set of devices.

1. Q-Connect: Q-Connect connects to the QL SER2 port allowing the computer to be used with virtually any asynchronous modem from 75 up to 9,600 baud, with full two-way buffering and flow control. Q-Connect was supplied with software on microdrive cartridge to support this and the other two modules. The software also supports both Prestel/videodata/videotext and VT100 emulation, as well as user-to-use communications.
2. Q-Mod:Q-Mod was a manual dial V23 modem operating at 1200/75 baud and 1200/1200 baud half duplex.
3. Q-Call:Q-Call provided traditional pulse/loop disconnect auto-dial and auto-answer.

Although the three modules were available separately, Tandata suggested that by using all three as a complete matched system full advantage could be taken of the integrated features of the Q-Connect's software.

The Tandata units were popular with QLers in the 1980s for use with the Prestel service and for Bulletin Board System connection.

This together with various accessories was kindly donated by Bob Haslam.